Welcome to the forum @guiltmanager
A user-contributed unofficial build of 3 DLL update for C:\Program Files\Duplicati 2 is linked from below.
Jottacloud Error 401 (Unauthorized) The post includes a download link for file OAuthFixJottacloud.zip
It seems fairly effective, though possibly not perfect. A scorecard summary is here, then posts continue.
There’s also a workaround of setting rclone to use Jottacloud then Duplicati to use rclone, but it’s longer.